Brake-testing device



April 28, 1931. H. CASLER ETAL f 1 03 BRAKE TESTING DEVICE Filed Oct. 20, 1923 -2 Sheets-Sheet 1 April 28, 1931.

H. CASLER ET AL BRAKE TESTING DEVICE Filed Oct. 20, 1928 2 Sheets-Sheet 2 Patented Apr, 28, 1931 UNITED STATES PATENT OFFICE HERMAN OASLER, OF GANASTOTA AND CHARLES P, GRIMES, F SYRACUSE; i NEW YORK i a BRAKE-TESTING DEVICE Application filed October 20, 1928. Serial No. 313,787.

Our invention relates to apparatus for testing motor vehicle brakes and has for itsob- Ject to provide a simple device of this nature by means of which it will'be possible to accurately determine the relative brake resistance of the respective wheels.

Other objects and advantages of the invention will be apparent as the description is considered in connection with the accom- 10, panylng drawings, in which:

F gure lis a plan view of the invention; F1gure 2 1s a section on the line 22 of Figure 1. i

Figure 3 is a section on the line 3-3 of Figure 1;and

Figure l is 'a Figure 1. v e i Referrln-g more particularly to the drawings wherein like reference numeralsrefer to corresponding parts throughout the sevsection on the line 44 of eral views 1 denotes the concrete floor of agarage or other building in which the devices is installed. Preferably the mechanism of the device is located in asuitable recess or cavity 2 so that the top of the device will be flush A with the top of the floor. However, if

deemed desirable the device may be mounted directly upon the floor, in which case, inclined approaches or ramps (not shown) would be employed.

In the embodiment illastrated base plates 3, four in number, mounted in cavities 2, support ball bearing frames 4, each comprising a plurality of anti-friction ball bearingsfi held in spaced relation by plates 6. These ball bearings support movable top plates 7,

7a, 7b and 7 a, one for each ball bearing frame 4 and base plate 3,- provided with side flanges 8 fitting over corresponding end flanges 9 formed upon the base plates It will be noted that the flanges 8 and 9 cooperate to prevent dirt from collecting en the bearings between the'movable plates-and the base 5 plates.

-When the movable top plates 7 are in nor- 1 mal or figure 2 position there .will be a space or clearance 10 between the respective rear end flanges 8 and 9 of the top plates 7 and base plates 3, the pur ose of which is to permit the top plates to moveforwardly'under serves to keep the ball bearings and their plates in their normal or Figure 2 position,

- relatively to the base plate. Movement of r the top plates with respect to the movement of the ball bearing frames will be at the ratio of 2 to 1, that is, when the top plates'are carried forward a distance of two inches under the load of a vehicle, the ball bearings 5 and plates 6 will be moved in a corresponding d1- rection a distance of one inch. In other words the ball bearing frames travel onehalf as far as the movable plates.

Connected to the forward ends of the rearmost pair of movable top plates 7 a and 7b are plungers I l- 14 which pro] ect through bearings -15-15 into a box 16 provided with a cover 17. These plungers respectively engage one arm of bell crank levers 18l8 pivotally mounted as at 1919"in the box 16, the other arms of the bell cranks '18-18' being pivotally connected to connecting rods 20-20 the free ends of which are provided with heads 21-21 in turn loosely received Within the enlarged portions 22.22' formed on the inner ends of connecting rods 23 -23. Coil springs 28-28 under more or less compression act to hold the heads 2121 at the end of the space provided for the heads and 26 -26. The free ends of the bell cranks 25' engage beneath the lower ends of verticallydisposed plungers 2727 the upper ends of which are respectively connectedto the bases '35' of sylphon bellows 29-29' mounted in the frame 30. ,Tubes 31 -31 con,-

, lieve any excessive pressure or vacuum in the system caused by the expansion or contraction of the fluid therein due to temperature k changes. Providing the tank or reservoir 33 operation of is placed a suitable distance above the sylphon bellows 29'29*then the weight of the liquid in tubes 31-31 and reservoir 33 will be adequate to return the movable top plates 7 7a-7 b 7c to normal position; However, should the height of reservoir 33 be such that weight of liquid be insufiicient to return the top plates to normal 01' Figure 2 position, air under pressure may be pumped into the top of reservoir 33 by means of the hand pump 34. As the construction and mounting of the forward movable platforms 7?) and 7 0 and the gauge and gauge mechanism thereforis identical withthatof the rear movable platforms or plates 7 and 7a description of theformer isdeemed unnecessary. a In practice the wheels of theautomobile, the brakes of which are being tested, are driven upon the movable platforms 7, 7a, 7b and 7c, and'while in motion, the brakes are simultaneously applied to the four wheels in the usual manner. The drag'pfthe wheels caused by the application of the'brakes will cause the movable platforms to move forwardly. As the description of the action of one movable late will sufiice for all, the

platform 7a'wvill'be briefly described. Forward movement of the platform 7a under the braking action of the right rear wheel of the vehicle will carry the plunger 14' forwardly thus rocking the bellcrank- 18' on its-pivot 19' and pulling the rods 20' and 23{ to the right, Figure 1, Lever 25 will then. be caused to elevate verticalplunger27 which in turn lifts the base 35' of 'thesylphon bellows 29 and contracts the latter, This contraction of the bellows causes the liquid in the bellows to rise and pass very ,slowlythrough orifices 37 into tank 33' thus creating a pressure intube 31' which is communicated throu h 'by-pa'ss 36' to gauge 32f.

'This gauge iso orjdinary and well known/ construction adapted to indicate a momentary pressure reading. Pressure of the liquid causes the vprimary rand secon'dary" ointers 38 and 39 respectively to move in t e usualmanner thus indicating the retarding force ofthc brake.-

a When the vehicle is removed from the testing device the' pressurejof the liquid will return" the movable platform and gauge actuating mechanism back to normal position, but shouldthepressure be insuflicient for this purpose, thehandpump. 34' is employed'to pum air into the tank 33, on top of the fluid, v

c eingtaken notto get-air into the system.

adapted to be longitudinally moved with re- 7,

. through said passage into said dgauge to indito said reservoir and gauges to cause said tomatically returned to zero position but the secondary pointer will remain at maximum pressure until brought back to zero reading on the gaugeby manual control (not shown). Having thusdesbribed our invention What wejclaim is: 1 v I 1. A testing device for brakes used on automobile wheels and the. like, comprising a base, a platform mounted on said base and spect thereto, when the brakes are applied while a Wheel is moving over said member, a liquid reservoir,a sylphon bellows having a passage leading to and in communication with said reservoir, a pressure indicator gauge communicating with said-passage, and connections between saiil bellows and movable platform whereby movement of the' latter will contract the bellows and force liquid cate the retarding force 'in brakes' 2. A testing device forbrakes used on auuced by the tomobile wheels and the like, comprising a 9(} 'pair of parallel base members, a pair of plat; forms independently movable mounted upon said base members and adapted to receive the Wheels of an automobile, aliquid reservoir mounted above and common to said platforms, a gauge for eachplatform, separate means connected to each platform and its associated gauge and communicating with the reservo'ir, said means adapted to force liquid gauges to register the thrust of its associated platform when the brakes areapplied to the wheels while the latter are moving along said members. i

3. A testing device for brakes used on antomobile wheels and the like, comprising a v pair of=parallel base me bers, a pair of platforms independentlymovable mounted upon said base members andadaptedrto receive the wheels of an automobilefa liquid, reservoir mounted above and common to said platforms, a gauge for each platform, separate means connected to each platform and its associated gauge adapted-to force a liquid to sa1d gauge to cause said g uge to register the thrust of its associated -latform when the brakes are applied to the wheels while the latter areunovin along said members,said separate means 1 elud ng a restricted passage communicating with said reservoir adapted to compensate for ex ansion, contraction or I leakage of saidliqui 5 L 4. A testing device for bra es used on vek hicles comprising amovable pl te adapted to*' be \overrun'and horizontally shiftedby a .yehicle wheel when the brakes are said wheel while moving over sai .gauge adapted to indicate the retarding force a plied to d plate,-a

actuating said movableplate, said gauge ac. tuated by a liquid mediumiunder pressure created by the movement of said movable plate, and means associated with said liquid medium compensating for expansion, contraction or leakage of said liquid medium.

5. A testing device for brakes used on vehicles comprising a movable plate adapted to be overrun and horizontally shifted by a vehicle wheel when the brakes are applied to said wheel while moving over said plate, a liquid reservoir adapted tocontain a substantially noncompressible liquid, a pressure gauge adapted to indicate the retarding force actuating said movable plate, a bellows operatively connected to said movable plate and having passages leading to said reservoir and to said gauge, the passing leading to said reservoir having a restricted opening whereby the expansion, contraction or leakage of liquid contained in said bellows and passage is compensated for. 

